Be careful with dependency handling. Consider an instance where you want to have the sale, sale_stock, and sale_specific add-ons installed, with sale_specific depending on sale_stock, and sale_stock depending on sale. To install all three, you only need to install sale_specific, as it will recursively install the sale_stock and sale dependencies. To update all three, you need to update sale, as this will recursively update the reverse dependencies, sale_stock and sale_specific.

Another tricky part with managing dependencies is when you add a dependency to an add-on that already has a version installed. Let's understand this by continuing with the previous example. Imagine that you add a dependency on stock_dropshipping in sale_specific. Updating the sale_specific add-on will not automatically install the new dependency, and neither will requesting the installation of sale_specific. In this situation, you can get very nasty error messages because the Python code of the add-on is not successfully loaded, but the data of the add-on and the models tables in the database are present. To solve this, you need to stop the instance and manually install the new dependency.